It's a big, important problem, since anyone can edit an article on Wikipedia, and the site's millions of users, rightly or wrongly, view its articles as authoritative. So how does the volunteer-written online encyclopedia distinguish trust from anti-trust?

The site's backers at the San Francisco-based Wikimedia Foundation say it will use a fancy algorthm called "WikiTrust" that assumes that content from experienced writers is more likely to be accurate. Wikipedia itself defines "trust" as "a relationship of reliance," and that's what WikiTrust accomplishes, without going much further: It delineates "trustworthiness" without making any warranty of "factuality."